Assembly with an instrument panel for a motor vehicle and a knee airbag

ABSTRACT

An airbag housing is carried on a formed part extending from a lower section of an instrument panel for a motor vehicle. The formed part forms at least a front section of an upper wall of a footwell assigned to the vehicle occupants. A knee airbag is disposed in the airbag housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/072,221 filed on 25 Feb. 2008. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to an assembly with an instrument panelfor a motor vehicle and a knee airbag.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

An assembly of the generic type is described, for example, in U.S. Pat.No. 6,217,059 B1 or US 2002/0171231 A1. Here, the housing whichaccommodates the airbag is located on the inner side of a lower sectionof the instrument panel and is rigidly fixed to this. The exit openingof the housing for the airbag here lies opposite the knee-shin area ofthe vehicle occupant to be protected, in other words of the driver orthe passenger, and is basically parallel to the surface of theinstrument panel. In case of operation, the knee airbag is inflatedbetween the instrument panel and the knee-shin area of the vehicleoccupant to be protected. The knee airbag serves primarily to preventthe forward movement of the pelvis of a vehicle occupant, in particularof a vehicle occupant who is not wearing a seat belt, from beingdisplaced forwards in case of a frontal collision.

SUMMARY

The significance of a knee airbag for the overall safety concept of amotor vehicle differs from region to region. In particular in the USA,where the wearing of seatbelts may not be a legal obligation, and whereit is often unusual to wear a seat belt, the significance of the kneeairbag for the safety concept of a motor vehicle is often extremelyhigh. In Europe, in contrast, where the legal obligation to wear aseatbelt is generally observed, the significance of the knee airbag forthe safety concept of a motor vehicle is often slight, or it can be moreuseful to save the weight of the knee airbag unit and to invest it inanother safety device.

This means that it is often the case that one and the same vehicle typeis offered in the USA with knee airbag, but in Europe without.

This again results in the need for development and manufacture ofdifferent instrument panels for one and the same type of vehicle.Because of the size and complexity of the instrument panels, this leadsto a very great deal of additional development and manufacturing work,with the associated costs.

Starting from this point, the present teachings have the task ofimproving the generic type of assembly in such a way that thedevelopment and manufacturing time and expense is decreased, if avehicle type is to be offered with the equipment variants with andwithout knee airbag.

According to the present teachings, the housing is not located on or inthe instrument panel, but on a formed part which follows on from thelower section of the instrument panel. Generally, therefore, this formedpart forms at least the front section of the upper wall of the footwellwhich is assigned to the vehicle occupants. Because the housing of theknee airbag is no longer a part of the instrument panel or is connectedwith it, the same instrument panel can always be used, independently ofwhether the vehicle is to be fitted with a knee airbag or not. It isonly necessary to stock two differently-formed parts, which, however,are considerably smaller and considerably less complex than theinstrument panel. It is even possible always to make use of the sameformed part, and, for the case that no knee airbag is to be used, tomake use of an additional cover element which covers the exit opening ofthe housing. Such a process becomes even more simple, as the exitopening of the housing in the arrangement according to the disclosurecan lie in an area which is not seen by the vehicle occupants, so thatexcessive time and expense with regard to a visible gap and similar canbe avoided.

As, during the expansion of an airbag, i.e. when the gas generator whichinflates the airbag is operated, considerable forces occur, as isalready known, it is often to be preferred if the formed part whichbears the housing is directly linked with a lateral strut of the motorvehicle.

In order to prevent gaps, the formed part should be connected with theinstrument panel. For reasons of simple assembly, it is preferred thatat least one part of the necessary connection elements is in the form ofa clip connection.

The housing which accommodates the knee airbag can be a separatecomponent which is connected with the formed part, or the housing can bean integral component of the formed part.

Further embodiments of the present teachings result from the furthersubclaims as well as from the embodiments now described in more detailby means of the Figures. The Figures are as follows:

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a lengthways section through the front area of an occupantcabin of a motor vehicle in schematic form;

FIG. 1 a illustrates the items shown in FIG. 1 in an equipment variantwithout a knee airbag;

FIG. 2 illustrates the items shown in FIG. 1 with the knee airbaginflated;

FIG. 3 illustrates the lower part of an instrument panel, a formed partand a steering column in a perspective view;

FIG. 4 illustrates the items shown in FIG. 3 in a different perspective;

FIG. 5 illustrates the formed part from FIGS. 3 and 4;

FIG. 6 illustrates the formed part from FIG. 5 in a bird's eye view fromDirection A;

FIG. 7 illustrates the lower part of an instrument panel and a formedpart according to a second embodiment of the invention in a side view;

FIG. 8 illustrates the items shown in FIG. 1 during inflation of theknee airbag, whereby the upper end of the knee airbag is connected withthe housing by means of a capture tape; and

FIG. 9 illustrates the items shown in FIG. 8 with the knee airbag fullyexpanded.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

FIG. 1 shows a schematic section through the front passenger side of amotor vehicle. In front of vehicle seat 19 there is instrument panel 10,under which footwell 50 is located. In the normal seat position, theknee-shin area 42 of passenger 40 is located in front of a lower sectionof instrument panel 10. The knee-shin area 42 is hereby at a distancefrom instrument panel 10.

As can be seen from FIG. 2, a knee airbag 32 is present which isinflated by a gas generator 30 in case of a frontal collision. At leasta part of this knee airbag 32 is located in fully expanded state betweenthe knee-shin area 42 of occupant 40 and a lower section of instrumentpanel 10. In particular when the passengers or drivers are not beltedin, knee airbag 32 prevents forward movement of the pelvis. Furthermore,collision of the sensitive knee-shin area 42 against instrument panel 10is prevented.

As can be seen from FIGS. 1 and 2, housing 22 of the knee airbag unit islocated on a formed part 20, which extends from the lower section ofinstrument panel 10 in the direction of the front of the vehicle, andhereby forms at least a part of the ceiling of footwell 60. Formed part20, which in general is an injection moulded part of plastic, herebylies basically horizontal. Housing 22 can be an integral part of formedpart 20, or housing 22 can be a separate component, which is rigidlyconnected with formed part 20. Footwell cladding 18 follows on at therear section of formed part 20.

In comparison with instrument panel 10, formed part 20 is a small andmechanically simple component. This means that only a comparativelyslight expenditure of cost and effort is required to manufacture it in aversion with airbag unit (see FIG. 1) and in a version without airbagunit (see FIG. 1 a). By these means, on the other hand, it is easy inone and the same type of vehicle to manufacture a version with kneeairbag and a version without knee airbag. It is only necessary in finalassembly with the first vehicle version to mount the first type offormed part 20 and in the second vehicle version to mount the secondtype of formed part connected to instrument panel 10. If the versionwith knee airbag unit is selected, this generally can be connected tothe same sensor system as the front airbag, which is always present.

FIGS. 3 to 6 show a first concrete embodiment of formed part 20, wherebyFIGS. 3 and 4 show formed part 20 in its mounted state at a lowersection of instrument panel 10 and FIGS. 5 and 6 show the formed part inits non-mounted state. It can be seen, that here the knee airbag is theknee airbag for the driver's side. The structure of formed part 20 willnow be explained in relation to FIGS. 5 and 6.

In the area of the front edge, there are latching elements 26 over whichformed part 20 can be latched on instrument panel 10. Immediately behindlatching elements 26 is housing 22, formed in one piece onto formed part20, in which the knee airbag and the gas generator are accommodated.Housing 22 continues to exhibit a cover 24 on the rear side, whichcovers a rear opening. The gas generator and the knee airbag are mountedthrough this rear opening. Basically opposite to this rear cover 24 isthe exit opening for the knee airbag, not shown here, which is closed bya cover element. This cover element can be formed in one piece withformed part 20 and can be surrounded by a set break line.

Next to housing 22 are fixing holes 23, through which screws extend whenin mounted state, which are screwed together with instrument panel 10.Together with latching elements 26, a sufficiently stable fixing offormed part 20 to instrument panel 10 results (see also FIG. 3). Thefixing element here basically surrounds housing 22, so that the forceswhich occur during expansion of the airbag can also be absorbed. Becauseof the inherent stiffness of formed part 20 it is not necessary toprovide additional fixing elements on the rear section of formed part20.

This means that mounting of the formed part on instrument panel 10 isextremely simple, as can particularly be seen in FIGS. 3 and 4: firstformed part 20 with its latching elements 26 is latched onto theinstrument panel 10 which is generally already mounted in the vehicleand then screwed together. By means of this modular structure, it isparticularly also possible to retrofit a knee airbag to a vehicle whichwas originally supplied in the version without knee airbag. It is onlynecessary to exchange the formed part which was originally mounted,which does not exhibit a knee airbag, for a formed part with a kneeairbag unit, and to connect the gas generator to the existing sensorsystem. As formed part 20, as already mentioned, forms the ceiling or apart of the ceiling of footwell 60, therefore formed part 20 exhibitsthrough-holes 28 for ventilation.

FIG. 7 shows a concrete version of the second embodiment of theinvention. Here, formed part 20 extends fully horizontally, so that theexit opening for knee airbag 32 lies in a horizontal plane. This has theparticular advantage that the transitional point between the lowersection of instrument panel 10 and formed part 20 cannot be seen by thevehicle occupants, so that here a relatively wide gap can be provided.It is possible to see here also that formed part 20 follows on directlyfrom a lateral strut 50 of the motor vehicle, with which it ispreferably also directly connected. This means that forces which occurwhen the knee airbag expands are led directly into this lateral strut,without placing stress on instrument panel 10. The invention is shownhere using a knee airbag unit for the passenger; the glove compartment14 of instrument panel 10 can be seen. Formed part 20 can in particularbe an injection moulded or deep-drawn part of plastic.

As can be seen in FIGS. 8 a and 9, a capture tape can be present runningoutside knee airbag 32, which helps to position knee airbag 32 betweeninstrument panel 10 and knee-shin area 42 of the vehicle occupants. Sucha capture tape 34 can be necessary, as depending on the particularembodiment, in particular in the embodiment shown in FIG. 7, the exitopening for knee airbag 32 is located fairly far away from the knee-shinarea 42 of the vehicle occupants.

While specific examples have been described in the specification andillustrated in the drawings, it will be understood by those skilled inthe art that various changes may be made and equivalence may besubstituted for elements thereof without departing from the scope of thepresent teachings as defined in the claims. Furthermore, the mixing andmatching of features, elements and/or functions between various examplesmay be expressly contemplated herein so that one skilled in the artwould appreciate from the present teachings that features, elementsand/or functions of one example may be incorporated into another exampleas appropriate, unless described otherwise above. Moreover, manymodifications may be made to adapt a particular situation or material tothe present teachings without departing from the essential scopethereof. Therefore, it may be intended that the present teachings not belimited to the particular examples illustrated by the drawings anddescribed in the specification as the best mode of presentlycontemplated for carrying out the present teachings but that the scopeof the present disclosure will include any embodiments following withinthe foregoing description and any appended claims.

What is claimed is:
 1. An assembly for a motor vehicle comprising: aninstrument panel; a formed part extended from a lower section of theinstrument panel; a housing carried on the formed part; and an airbag inthe housing when stored and which on activation is inflated between thelower section of the instrument panel and a knee-shin area of a vehicleoccupant to be protected; wherein the formed part is connected with theinstrument panel; and wherein the airbag is configured to include aforward end and a rearward end which both are introduced into a footwellof the motor vehicle at a point forward of a forward edge of theinstrument panel and upon inflation the forward end is disposedimmediately below the housing.
 2. An assembly for a motor vehiclecomprising: an instrument panel having a lower side that terminates at aforward edge; a footwell cladding defining a first portion of a ceilingof a footwell of the motor vehicle and terminating at a rearward edge,an opening defined between the forward edge of the instrument panel andthe rearward edge of the footwell cladding; a first formed part sizedand shaped to be selectively insertable into the opening so as to extendin a direction toward a front of the motor vehicle from the forward edgeof the instrument panel to the rearward edge; a housing carried by thefirst formed part, the housing defining an airbag exit opening; and anairbag in the housing when stored and which on activation extendsthrough the exit opening, into the footwell from a point forward of theforward edge of the instrument panel and is inflated from the pointforward of the forward edge of the instrument panel to a positionbetween the lower side of the instrument panel and a knee-shin area of avehicle occupant to be protected wherein the airbag is configured toinclude a forward end and a rearward end which both are introduced intothe footwell at the point forward of the forward edge of the instrumentpanel and upon inflation the forward end is disposed immediately belowthe housing.
 3. The assembly according to claim 1, wherein the formedpart is selectively connected with the forward edge of the instrumentpanel.
 4. The assembly according to claim 1, wherein the formed part islatched together with the forward edge of the instrument panel by clipconnections.
 5. The assembly according to claim 1, wherein the formedpart is selected from a group including an injection moulded part and adeep-drawn part of plastic.
 6. The assembly according to claim 1,wherein the housing is an integral part of the formed part.
 7. Theassembly according to claim 1, wherein the housing is a separate elementwhich is connected with the formed part.
 8. The assembly of claim 1,wherein the airbag is configured upon inflation to include an upper sidein communication with the housing.
 9. The assembly of claim 3, whereinthe airbag is configured upon inflation such that the rearward end isdisposed higher than the forward end.
 10. The assembly of claim 1,wherein the airbag is configured upon inflation to have a length betweena forward end and a rearward end, the length being greater than a heightgenerally perpendicular to the length.
 11. The assembly of claim 2,wherein a forward end of the airbag is disposed immediately below thehousing.
 12. An assembly for a motor vehicle having a seat with aheadrest comprising: an instrument panel for generally facing a vehicleoccupant, the instrument panel having a lower side that terminates at aforward edge; a footwell cladding defining a first portion of a ceilingof a footwell of the motor vehicle, the first portion terminating at arearward edge that is spaced apart from the forward edge so as to definea gap between the instrument panel and the footwell cladding; a firstformed part sized and shaped to be selectively insertable into the gapso as to forwardly extend from the forward edge of the instrument paneltoward the rearward edge of the cladding, the first formed part defininga second portion of the ceiling of the footwell of the motor vehicle,the first formed part defining an integrally formed housing extendingfrom an upper side thereof and defining an exit opening; and an airbagnormally stored in the integrally formed housing and which uponactivation extends through the exit opening, into the footwell and isinflated between the lower side of the instrument panel and a knee-shinarea of the vehicle occupant, wherein an imaginary straight line extendsfrom any first point on the headrest to any second point on the assemblysuch that the imaginary line always intersects the instrument panel. 13.The assembly of claim 6, wherein the airbag is configured upon inflationto include an upper side in communication with the housing.
 14. Theassembly of claim 7, wherein the airbag is configured upon inflation toinclude a forward end and a rearward end, the forward end disposedimmediately below the housing.
 15. The assembly of claim 1, wherein theairbag is configured upon inflation such that the rearward end isdisposed higher than the forward end.
 16. The assembly of claim 7,wherein the airbag is configured upon inflation to have a length betweena forward end and a rearward end, the length being greater than a heightgenerally perpendicular to the length.
 17. The assembly of claim 1,wherein a forward end of the airbag is disposed immediately below thehousing.
 18. An assembly in combination with a motor vehicle having aninstrument panel and a seat with a headrest comprising: a first formedpart configured to be selectively disposed relative to the instrumentpanel so as to extend in a direction toward a front of the motor vehiclefrom a forward edge of the instrument panel, the first formed partdefining at least a portion of a ceiling of a footwell of the motorvehicle; a housing carried by the first formed part and defining an exitopening; and an airbag normally stored in the housing, extendablethrough the exit opening into the footwell from a point forward of theforward edge of the instrument panel, and inflatable from the pointforward of the forward edge of the instrument panel to a positionbetween a lower side of the instrument panel and a knee-shin area of avehicle occupant to be protected; wherein the airbag is configured toinclude a forward end and a rearward end which both are introduced intothe footwell at a point forward of a forward edge of the instrumentpanel and upon inflation the forward end is disposed immediately belowthe housing, and wherein an imaginary straight line extends from anyfirst point on the headrest to any second point on the assembly suchthat the imaginary line always intersects the instrument panel.
 19. Amotor vehicle having an occupant compartment, the motor vehiclecomprising: an airbag subassembly inserted into an opening in a footwellof the motor vehicle, the airbag subassembly including an airbag and ahousing defining an exit opening for the airbag, the airbag disposed inthe housing when stored and which on activation extends through the exitopening, into the footwell from a point forward of a forward edge of aninstrument panel and is inflated from the point forward of the forwardedge of the instrument panel to a position between the instrument paneland a knee-shin area of a vehicle occupant to be protected; and anoccupant seat including a headrest, wherein an imaginary straight lineextends from any first point on the headrest to any second point on thesubassembly such that the imaginary line always intersects theinstrument panel.
 20. The assembly of claim 18, further comprising acapture strap coupled to the airbag about an exterior thereof such thatthe capture strap runs outside the airbag and facilitates positioningthe airbag in the knee-shin area.